【Python】进程-锁(1)

#第二题，做一个加减乘除的考试系统，自动出题，自动判对错，并统计结果，一次考试10道题
import random
symbols=["+","-","*","/"]

total_count=0
correct_count=0
incorrect_count=0

while 1:
    random_number1=random.randint(0,11)
    random_number2=random.randint(0,11)
    random_symbol=random.choice(symbols)

    if random_symbol=="/" and random_number2==0:
        continue
    elif random_symbol=="/" and random_number1%random_number2 !=0:
        continue

    expression=str(random_number1)+" "+random_symbol+" "+str(random_number2)
    answer=eval(expression)
  
    print expression,"= ",
    while 1:
        try:
            user_answer=int(raw_input(""))
            break
        except:
            print "input is not a number,try again" 

    if user_answer==answer:
        print "your answer is right"
        correct_count+=1
        total_count+=1
    else:
        print "your answer is wrong,the right answer is %s" %answer
        incorrect_count+=1
        total_count+=1
    if total_count==3:
        break

print "correct answer is %s" %correct_count
print "incorrect answer is %s" %incorrect_count

#第三题：计算一个二维矩阵的正对角线、反对角线、周边数之和
a=[ [1,2,3],
    [4,5,6],
    [7,8,9]
  ]


#遍历正对角线
count=0
for i in range(len(a)):
    for j in range(len(a[0])):
        if i==j:
            count+=a[i][j]
print count

#遍历反对角线
#[0][2]
#[1][1]
#[2][0]
count=0
column=len(a[0])-1  
for i in range(len(a)):
    count+=a[i][column-i]
print count
        

#周边元素和
#[0][0]
#[0][1]
#[0][2]
#[1][0]
#[1][2]
#[2][0]
#[2][1]
#[2][2]
count=0
for i in range(len(a)):
    for j in range(len(a[0])):
        if i==0 or i==len(a)-1 or j==0 or j==len(a[0])-1:
            print i,j
            count+=a[i][j]
print count



#练习：加锁
from multiprocessing import Process,Lock
import time
def lock_lock(lock,num):
    lock.acquire()
    time.sleep(0.2)
    print "hello Num: %s" %num
    lock.release()

if __name__=="__main__":
    lock=Lock()
    for num in range(20):
        p=Process(target=lock_lock,args=(lock,num))
        p.start()

#练习：多进程写一个文件，加锁
from multiprocessing import Process,Lock
import time

def write(lock,num):
    lock.acquire()
    with open("e:\text40.txt","a+") as f:
        f.write("wangjing:%s
" %(num))
    lock.release()

if __name__=="__main__":
    lock=Lock()
    for i in range(5):
        p=Process(target=write,args=(lock,i))
        p.start()
        p.join()
    print "write file done"



#练习：多把锁
import multiprocessing
import time
def worker(s, i):
  s.acquire()
  print(multiprocessing.current_process().name + " acquire")
  time.sleep(i)
  print(multiprocessing.current_process().name + " release")
  s.release()

if __name__ == "__main__":
  # 设置限制最多3个进程同时访问共享资源
  s = multiprocessing.Semaphore(3)
  for i in range(5):
    p = multiprocessing.Process(target = worker, args = (s, i * 2))
    p.start()